Media preservation is an imperfect art. In the end, it is about maintaining a faithfulness to the original image/signal/presentation, within the confines of what is possible as impacted by condition of the original, existing technology, desired use, and (shhh) budget. There are options for reformatting both technological (what machinery, stocks, and other equipment is used) and artistic (color-timing, levels, stylus selection) which affect the end product, for better or for worse.
Media preservation is an impermanent art. In the end, our efforts, too, will fade away and require further effort. And our decisions will impact the options of those who follow us, for better or for worse.
In making preservation decision we must be aware of our own interpretive limitations, as well as the technological limitation of the media we are working with. There is no perfect medium, and anyone trying to sell you on that is...trying to sell you something. Caveat emptor. Cavete a mediorum.
When dealing with target digital formats we try to make these caveats transparent to aid decision making -- such factors as looking at how proprietary something is, how tied it is to particular systems, or how complex and processor heavy it is. A certain format may offer benefits such as smaller sizes or improved visual quality, but those may be outweighed by usability and portability concerns that negatively impact collection management. These facts do not instantly disqualify all digital formats for preservation use, but they should influence one's decision on which format to select.
We could do that same exercise with videotape, but the caveat there is, basically, that that's an insane option.
But really what got me thinking on this topic is what I call the storage caveat. Film still is certainly a valid preservation format for film. There are definitely benefits of quality, presentation, and stability that film provides. But the pea that gets under my mattress is the small print of "under the right storage conditions", as in film is stable for X gagillion years under the right storage conditions.
What are these right storage conditions? Pretty much cold and frozen (14℉-45℉), with limited seasonal fluctuation. Never mind the physical space and shelving required for storage of film reels. How many institutions can actually maintain such environmental conditions reliably? Especially considering that most collections will be mixed with video, audio, photography, and paper, as well as the fact that many institutions are experimenting with shutting down HVAC systems overnight to save on electricity costs? Space wise, cost wise, and environmentally wise film cannot be a one-size-fits-all solution -- as I have seen it pushed through certain venues or grant programs -- nor is it necessarily the right solution for film. It is an option.
Another caveat that came to me while thinking about this is the fallacy of physicality. One of the arguments for the primacy of film is the idea that, even if the technology is gone, you can still pick up a film and view it by eye with out a projector. Yes, but what about the audio track? Can you read a magnetic stripe or optical track with your eyes? Can you really understand a film without the audio? Sure, maybe if it's silent, but even then there are interstitials or accompanying lectures (or informal narration as with home movies) which give explanation or context to the image. Why would the audio piece be ignored in such a scenario? Are we willing to forgo it? (I know if it were full coat mag track I would like very much to forget it and not deal with it...) Is that really an argument for preservation if such reasoning contains the purposeful future fragmentation and decontextualization?
In truth, like file-based works, film is a complex format that extends well beyond image, emulsion, and base. The work itself may exist in multiple pieces and components -- that may or may not be film -- which are connected merely through labeling or metadata or, perhaps, physical proximity...Or not at all. The persistence of the physical reel is not preservation of the cinematic experience nor preservation of the entire work, nor is that physical persistence guaranteed.
The caveat, no, the fact of media preservation is that migration is the only long term solution and that all formats will degrade or obsolesce much sooner than we anticipated. Art imitates life.
Life is a caveat, old chum.
--- Joshua Ranger